/*
 * Copyright (c) 2011 Nathan Byrd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package org.stackconfig.web.gwt.client.widgets;

import com.google.gwt.user.client.ui.AcceptsOneWidget;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.LayoutPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Single widget panel, used instead of SimplePanel in order to keep layout
 */
public class SimpleLayoutPanel extends LayoutPanel implements AcceptsOneWidget {
    private Widget singleWidget;

    @Override
    public void setWidget(IsWidget widget) {
        setSingleWidget(asWidgetOrNull(widget));
    }

    public void setSingleWidget(Widget widget) {
        if(widget == singleWidget) {
            return;
        }

        if(singleWidget != null) {
            super.remove(singleWidget);
        }

        singleWidget = widget;
        if(singleWidget != null) {
            super.add(singleWidget);
        }
        
    }
}
